The future is written in stone

StFX geologist Donnelly Archibald pursues research in Madagascar

By Lois Ann Dort    

ANTIGONISH – Readers of the Guysborough Journal may recognize the name Donnelly Archibald; he’s been a steady feature in sporting news recently as pitcher for the Pomquet Acadians, the AGR Fastpitch League champions of 2017, and recently part of the national championship winning East Hants Mastodons. But the Aspen, Guysborough County native has yet another passion: geology, and it has taken him places beyond his wildest dreams, to the famed island of Madagascar off the southeast coast of Africa.

As a child and youth, Archibald, who now teaches in the Department of Earth Sciences at StFX, admits he had no particular penchant for geology. He wasn’t an amateur rock-hound but he did enjoy being outdoors. “I was outside all the time; hiking, fishing, working in the woods. But I didn’t become interested in rocks until I got to StFX.”

Initially enrolled in chemistry and biology, Archibald switched to geology in his second year after watching an interesting television show on geology and talking with Earth Sciences professor Brendan Murphy.

He went on to complete a BSc honours degree in Earth Sciences, a Masters Degree at Acadia University and a PhD in Geology at the University of Adelaide, Australia.

When asked about the work he conducted for his PhD research in Madagascar, Archibald said jokingly, “It’s nothing like the movie.” Although he did spend some time as a tourist in country, most of his days were spent studying and collecting granite rocks working to unravel the tectonic evolution of Central Madagascar during the Neoproterozoic (ca. 1000-541 million years ago).

“I was very fortunate to work there....most of our time was spent away from major cities, away from the tourist traps, looking at rocks,” said Archibald.

Archibald’s research focused on, “The tectonic environment in Madagascar in that time period. Granite rocks are the representation of tectonic events; subduction (movement of one plate under another) or plates moving apart. Depending on the chemistry of the granites you can tell the tectonic environment in which they were formed.”

While this research sounds like a purely academic pursuit, not applicable to present day realities, Archibald explained how the past is the key to the future. “If we understand the way that the plates move and plate tectonics in the past, we can predict the way that plate tectonics might go in the future. Also, different tectonic environments can host different mineral environments as well. Which has socio-economic implications.” In layman’s terms this determines what neighbourhood we’ll find ourselves in after a few millennia and where we might find mineral assets in the current geological climate.

Archibald’s work in Madagascar took place in June 2013 and Sept. 2014 and he’s still publishing papers on the work he conducted in the field. He shipped 250 kilograms of rocks from the island nation back to Canada at a cost of $100 a kilogram.

Archibald has definitely found his passion in geology and would love to go back to Madagascar. In the meantime he would like to look more closely at rock formations in Canada and close to home in Cape Breton.

“Three hundred and eighty million years ago there would have been a big mountain range here. These minerals,” said Archibald holding a rock sample of staurolite crystals from nearby Glenelg, “would have formed probably 15 to 20 kilometres below the surface.”

Currently Archibald is working at StFX, wrapping up some loose ends on his PhD research and some projects he was collaborating on in the Congo and Mozambique and trying to start his own independent research program.